NATURAL HISTORY AND PHYSIOGRAPHY OF NEW BRUNSWICK. 319 
Its bed is of shingle or sand, with occasional boulders ; there are 
many long stillwaters separated by short rips of moderate fall, 
•or by long smooth gravel reaches ; the bank vegetation is dense 
and attractive ; and altogether we have an extremely pleasant 
river. Two distinct types, with correlated beds, banks and 
scenery occur upon all these rivers in more or less regular alter- 
nation. There is, first , the intervale type, with low banks, elm 
.and maple clad, often backed by level river terraces, with bed and 
banks of smooth gravel, sand and even mud, and with many 
stillwaters separated by gravel rips. Second , there is the clay 
bank type, in which the banks are steep, rounded terraces of 
boulder clay, bearing white birch, while the river bed is swift, 
shallow and obstructed with boulders left by the washing away 
■of the finer materials, and forming often heavy rapids. In the 
settled district, the intervale type is well settled, while the clay 
Tank type is not. Extensive ledges occur here and there upon 
■one bank or the other (often forming considerable cliffs), and 
even partly in the bed of the river, but in no case does the river 
flow completely over ledges, and in no part is it post-glacial. In 
general, the valley becomes broader downward, and in its lower 
part it is thickly settled, especially on the intervales and terraces, 
and it becomes a very attractive river and very much larger than 
our maps imply. On one of its most typical parts the Dungarvon 
enters, apparently a smaller river than the Renous. Finally it 
•empties through a somewhat narrower valley by a rather insigni- 
ficant mouth into the Miramichi, forming, in all probability, as 
•earlier pointed out (Note 50) the true morphological head of the 
part of the Miramichi below it. 
In general the physiographic history of this part of the river 
•seems plain. It is one of the ancient parallel series crossing the 
Carboniferous plain from southwest to northeast. One possible 
alteration of the original course may be noted. About half way 
irom the South Branch to the Dungarvon the direction of the 
valley changes, its upper part pointing off to the Little South- 
west Mirimichi ; it seems possible that it may at first have had 
that course, the part thence to the Dungarvon being newer, and 
the Renous below the Dungarvon originally belonging to the 
latter river. 
